Hach DR/850, Procedures Manual, Page: 97 / 460

97
Summary of Method
The sample is first diluted in a Test ‘N Tube™. In the presence of
a cyanoferrate catalyst, monochloramine (NH
2
Cl) in the sample
reacts with a substituted phenol to form an intermediate
monoimine compound. The intermediate compound couples with
excess substituted phenol to form a green indophenol. Color
intensity is proportional to the amount of monochloramine
present in the sample.
Safety
Good safety habits and laboratory techniques should be used
throughout the procedure. Consult the Material Safety Data Sheet
(MSDS) for information specific to the reagent used.
Instrument Setup
This procedure will add the current method as a new Hach
program to your DR/850 or DR/890 instrument.
1. Turn the instrument on by pressing the
ON
key.
2. Press the
SETUP
key.
3. Press the down arrow key until the prompt line shows
USER
.
4. Press the
ENTER
key.
5. Key in “8138”, then press
ENTER
.
6. Key the number in the “Enter” column corresponding to line
number 1 on the display. Press
ENTER
. Repeat for lines 2–56
on the display.
Table 13
Line number on display Enter Line number on display Enter
1 111 29 108
2 42 30 78
3 73 31 0
4 0 32 0
5 0 33 0
6 0 34 0
7 0 35 63
8 0 36 58
9 0 37 61
10 0 38 112
CHLORAMINE, MONO, High Range, continued